Cecal Microbial Community Research Articles

Effects of Cassava Pellets and Enzymes Addition on Growth Performance, Meat Quality, Serum Biochemical Indices and Cecum Microbiota of Broilers

The composition of feed significantly influences the growth performance and gut microbiota of broiler chicks, impacting their overall health and productivity. This study aimed to investigate the effects of cassava pellets and enzymes supplementation on the growth performance, meat quality, serum biochemical indices, and cecal microbial community of broiler chicks. A total of 144 healthy 1-day-old AA broilers were randomly assigned to six dietary groups: basal diet (K1), basal diet + 5% cassava pellets (K2), basal diet + 10% cassava pellets (K3), basal diet + 20% cassava pellets (K4), basal diet + 20% cassava pellets + 0.3% tannase (K5), and basal diet + 20% cassava pellets + 0.3% tannase + 2500 U/kg α-amylase (K6). At 21 days, growth performance, meat quality, serum biochemical indices, and cecal microbial composition were analyzed. Compared to K1, the end weight was significantly higher in the K3 and K5 groups (P < 0.05); average daily weight gain was significantly higher in the K3 and K6 groups (P < 0.05); and the feed-to-weight ratio was lower in the K3 group (P < 0.05). Cecal microbiota analysis revealed that the Bacteroidetes, Firmicutes, and Proteobacteria were the dominant phyla. Alpha diversity showed a significant increase in the Chao index in the K3 group and in the Shannon and Simpson indices in the K6 group compared to the K1 group (P < 0.05). Beta diversity indicated similar microbial compositions across groups. LEfSe analysis showed increased numbers of specific bacteria in treated groups. Serum analysis revealed significantly higher ALT levels in the K4 group and higher IBIL levels in the K5 group (P < 0.05), with Bacteroides plebeius and Megamonas positively correlated with ALT (P < 0.05). The addition of 10% cassava pellets to the diet improved the growth performance and meat quality of broilers from 1 to 21 days of age and enhanced the microbial composition, providing valuable insights for optimizing broiler diets and improving economic returns.

Metagenomic profiling of cecal microbiota and antibiotic resistome in rodents

The rodent gut microbiota is a known reservoir of antimicrobial resistance, yet the distribution of antibiotic resistance genes (ARGs) within rodent cecal microbial communities and the specific bacterial species harboring these ARGs remain largely underexplored. This study employed high-throughput sequencing of 122 samples from five distinct rodent species to comprehensively profile the diversity and distribution of ARGs and to identify the bacterial hosts of these genes. A gene catalog of the rodent cecal microbiome was constructed, comprising 22,757,369 non-redundant genes. Analysis of the microbial composition and diversity revealed that Bacillota and Bacteroidota were the dominant bacterial phyla across different rodent species, with significant variations in species composition among the rodents. In total, 3703 putative antimicrobial resistance protein-coding genes were identified, corresponding to 392 unique ARG types classified into 32 resistance classes. The most enriched ARGs in the rodent cecal microbiome were associated with multidrug resistance, followed by glycopeptide and elfamycin antibiotics. Procrustes analysis demonstrated a correlation between the structure of the microbial community and the resistome. Metagenomic assembly-based host tracking indicated that most ARG-carrying contigs originated from the bacterial family Oscillospiraceae. Additionally, 130 ARGs showed significant correlations with mobile genetic elements. These findings provide new insights into the cecal microbiota and the prevalence of ARGs across five rodent species. Future research on a wider range of wild rodent species carrying ARGs will further elucidate the mechanisms underlying the transmission of antimicrobial resistance.

A-079 Investigation of gut microbial flavonoid catabolites in metabolic diseases

Abstract Background Flavonoids, a secondary metabolite found in plant-based diets, have gained attention in the last decade for their antioxidative properties in high-fat diet induced obesity animal models and human studies. Previous work showed that certain gut microbiota members can metabolize flavonoids into monophenolic acids (MPAs), and some of these MPAs have similar effects to insulin when administered orally. Our objective is to explore the microbiome connection between flavonoid-rich diets and improved metabolic parameters in obesity. We hypothesize that flavonoid-supplemented diets are most effective in the presence of gut microbiota capable of MPA formation and that these bacterial metabolites are the main bioactive compounds responsible for the improved metabolic parameters Methods To investigate our hypothesis, we fed male and female C57BL/6 mice a high-fat control diet (HFD) or the same diet supplemented with 1% MPA or 1% berry extract for 12 weeks. Each group was further divided into subgroups that received regular drinking water (RW) or antibiotic water (ABW) to suppress gut microbial communities. A range of metabolic parameters, such as body weight, lean and fat mass, glucose and insulin tolerance, histological assessment of liver cells, quantification of liver injury biomarkers, transcriptional changes in metabolically active tissues, and glucose and lipid metabolism pathways, were monitored. Additionally, 16s sequencing was performed on the cecal microbial composition of each group. Results Mice on HFD control with RW or ABW showed prominent hepatic steatosis and an increase in liver lipids accumulation demonstrated by a significant decrease in the activation of lipid metabolism pathways. Similarly, mice on HFD with 1% MPA and RW or ABW exhibited a significant reduction in hepatic steatosis and an increase in the activation of the lipid metabolism pathways, regardless of gut microbiota presence. In line with our hypothesis, mice on HFD with 1% berry extract and RW showed a similar reduction in hepatic steatosis to both 1% MPA groups. However, mice on HFD with 1% berry extract and ABW displayed noticeable hepatic steatosis, indicating the loss of the positive effect provided by berry extract metabolites once gut microbiota was depleted by antibiotics. Insulin tolerance test revealed a gut microbial effect as well in the HFD with 1% berry extract, illustrated by a significant reduction in glucose levels after insulin injection and an increase in insulin sensitivity. In contrast, the HFD control mice experienced an increase in glucose levels after insulin injection and insulin resistance. Although there were notable decreases in fasting blood glucose, there were no significant effects on fat and lean mass, insulin, glucagon, or liver injury marker levels. Finally, the mice on HFD with 1% berry extract had significantly more diverse cecal microbial communities than those fed HFD or HFD with 1% MPA. Conclusions Feeding mice a flavonoid-rich diet in the presence of intact gut microbiome can improve metabolic parameters associated with metabolic diseases, potentially preventing, or reversing these diseases. Our findings suggest promising avenues for treatment, such as dietary flavonoid supplementation with concurrent gut microbial probiotic therapy.

A 16S RNA Analysis of Yangzhou Geese with Varying Body Weights: Gut Microbial Difference and Its Correlation with Body Weight Parameters.

China is a major goose-raising country, and the geese industry plays a significant role in animal husbandry. Therefore, goose growth performance (body weight) is a critical topic. Goose gut microbiota influences weight gain by regulating its energy metabolism and digestion. Additionally, the impact of cecal microbial community structure on goose growth and development, energy metabolism, and immunity has been examined. However, most studies have used different additives or feeds as variables. Improving the understanding of the dynamic changes in gut microbial communities in geese of different body weights during their growth and development and their correlation with the host's body weight is necessary. In this study, the cecal microbiota of healthy Yangzhou geese with large (L) and small (S) body weights, all at the same age (70 days old) and under the same feeding conditions, were sequenced using 16S rRNA. The sequencing results were annotated using QIIME2 (classify-sklearn algorithm) software, and the linkET package was used to explore the correlation between intestinal microorganisms and the body weight of the Yangzhou goose (Spearman). At the phylum level, the Firmicutes/Bacteroidetes ratio in the large body weight group was approximately 20% higher than that in the small body weight group, with Bacteroidetes and Firmicutes exhibiting a highly significant negative correlation. At the genus level, Bacteroides constituted the most abundant microbial group in both groups, although the Prevotellaceae_Ga6A1_group exhibited a higher abundance in the large than the small weight group. Spearman correlation analysis and the linkET package were used to analyze the correlation between cecal microflora and production performance indicators that showed significant differences between the two groups and showed that birth weight was significantly positively correlated with Deferribacterota at the phylum level. At the genus level, leg and chest muscle weights exhibited significant positive correlations with Prevotellace-ae_Ga6A1_group, suggesting its critical role in promoting the growth and development of goose leg and chest muscles. A significant negative correlation was observed between [Ruminococ-cus]_torque and Prevotellaceae_Ga6A1_group. These findings offer a crucial theoretical foundation for the study of gastrointestinal microorganisms and provide insights into the development and formulation of poultry probiotics.

Prebiotic galactooligosaccharide improves piglet growth performance and intestinal health associated with alterations of the hindgut microbiota during the peri-weaning period

BackgroundWeaning stress reduces growth performance and health of young pigs due in part to an abrupt change in diets from highly digestible milk to fibrous plant-based feedstuffs. This study investigated whether dietary galactooligosaccharide (GOS), supplemented both pre- and post-weaning, could improve growth performance and intestinal health via alterations in the hindgut microbial community.MethodsUsing a 3 × 2 factorial design, during farrowing 288 piglets from 24 litters received either no creep feed (FC), creep without GOS (FG–) or creep with 5% GOS (FG+) followed by a phase 1 nursery diet without (NG–) or with 3.8% GOS (NG+). Pigs were sampled pre- (D22) and post-weaning (D31) to assess intestinal measures.ResultsCreep fed pigs grew 19% faster than controls (P < 0.01) prior to weaning, and by the end of the nursery phase (D58), pigs fed GOS pre-farrowing (FG+) were 1.85 kg heavier than controls (P < 0.05). Furthermore, pigs fed GOS in phase 1 of the nursery grew 34% faster (P < 0.04), with greater feed intake and efficiency. Cecal microbial communities clustered distinctly in pre- vs. post-weaned pigs, based on principal coordinate analysis (P < 0.01). No effects of GOS were detected pre-weaning, but gruel creep feeding increased Chao1 α-diversity and altered several genera in the cecal microbiota (P < 0.05). Post-weaning, GOS supplementation increased some genera such as Fusicatenibacter and Collinsella, whereas others decreased such as Campylobacter and Frisingicoccus (P < 0.05). Changes were accompanied by higher molar proportions of butyrate in the cecum of GOS-fed pigs (P < 0.05).ConclusionsGruel creep feeding effectively improves suckling pig growth regardless of GOS treatment. When supplemented post-weaning, prebiotic GOS improves piglet growth performance associated with changes in hindgut microbial composition.

Campylobacter jejuni and casein hydrolysate addition: Impact on poultry in vitro cecal microbiota and metabolome.

This study investigates the impact of casein hydrolysates on the poultry ceca inoculated with Campylobacter focusing on microbial molecular preferences for different protein sources in the presence of Campylobacter jejuni. Three casein sources (intact casein (IN), casein enzyme hydrolysate (EH), and casein acid hydrolysate (AH)) were introduced to cecal contents in combination with inoculated C. jejuni in an in vitro model system incubated for 48 h at 42°C under microaerophilic conditions. Samples were collected at 0, 24, and 48 h. Genomic DNA was extracted and amplified using custom dual-indexed primers, followed by sequencing on an Illumina MiSeq platform. The obtained sequencing data were then analyzed via QIIME2-2021.11. Metabolite extracts were analyzed with ultra-high-performance liquid orbitrap chromatography-mass spectrometry (UHPLC-MS). Statistical analysis of metabolites was conducted using MetaboAnalyst 5.0, while functional analysis was performed using Mummichog 2.0 with a significance threshold set at P < 0.00001. DNA sequencing and metabolomic analyses revealed that C. jejuni was most abundant in the EH group. Microbial diversity and richness improved in casein supplemented groups, with core microbial differences observed, compared to non-supplemented groups. Vitamin B-associated metabolites significantly increased in the supplemented groups, displaying distinct patterns in vitamin B6 and B9 metabolism between EH and AH groups (P < 0.05). Faecalibacterium and Phascolarctobacterium were associated with AH and EH groups, respectively. These findings suggest microbial interactions in the presence of C. jejuni and casein supplementation are influenced by microbial community preferences for casein hydrolysates impacting B vitamin production and shaping competitive dynamics within the cecal microbial community. These findings underscore the potential of nutritional interventions to modulate the poultry GIT microbiota for improved health outcomes.

Impact of whole grain highland hull-less barley on the denaturing gradient gel electrophoresis profiles of gut microbial communities in rats fed high-fat diets.

While next-generation sequencing has overshadowed polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), the latter still holds promise for advancing gut microbiota analysis due to its unique advantages. In this study, we used optimized nested PCR-DGGE to investigate the gut microbiota profile of high-fat diet rats after administering whole grain highland hull-less barley. High-throughput sequencing was employed to validate the DGGE results. Our results proved the reliability of PCR-DGGE for analyzing the dominant taxonomic composition while also providing visual evidence of a notable relationship between the composition of cecal and fecal microbial communities, highlighting substantial differences in both richness and abundance.

Dietary honokiol supplementation improves antioxidant capacity, enhances intestinal health, and modulates cecal microbial composition and function of broiler chickens

Honokiol is a multifunctional polyphenol present in Magnolia officinalis. The effects of honokiol as a supplement in broiler chicken diets, and the underlying mechanisms, remain unclear. Therefore, the aim of the present study was to investigate the effects of honokiol on the growth performance, antioxidant capacity, and intestinal histomorphology of broiler chickens and to explore the underlying mechanisms. In total, 240 one-day-old broilers were randomly allocated to 5 dietary treatments, with 6 replicate pens and 8 birds per pen. Birds were fed a basal diet supplemented with 0 (blank control, BC), 100, 200, or 400 mg/kg honokiol (H100, H200, and H400), or 200 mg/kg bacitracin zinc (PC) for 42 d. The results showed that H200 and H400 increased body weight gain (BWG) and decreased feed conversion ratio (FCR) during the starter period (P < 0.05). H100 and H200 increased total superoxide dismutase (T-SOD) activity in the serum and decreased malondialdehyde (MDA) amount in the jejunum on d 42 (P < 0.05). Moreover, H100 increased villus height-to-crypt depth ratio in both the jejunum and ileum on d 21 (P < 0.05). PCR analysis showed that honokiol upregulated intestinal expression of glutathione peroxidase (GSH-Px) and downregulated intestinal expression of inducible nitric oxide synthase (iNOS) on d 42 (P < 0.05). The Shannon index, which represents the microbial alpha diversity, was reduced for the PC, H200, and H400 groups. Notably, honokiol treatment altered the cecal microbial community structure and promoted the enrichment of several bacteria, including Firmicutes and Lactobacillus. Higher production of short-chain fatty acids was observed in the cecal digesta of H100 birds, accompanied by an enriched glycolysis/gluconeogenesis pathway, according to the functional prediction of the cecal microbiota. This study provides evidence that honokiol improves growth performance, antioxidant capacity, and intestinal health of broiler chickens, possibly by manipulating the composition and function of the microbial community.

Alpiniae oxyphyllae fructus improves production performance and egg quality of laying breeder hens by regulating reproductive hormones, antioxidant function, immunity and intestinal health

Alpiniae oxyphylla fructus was extensively utilized both as dietary supplements and traditional herbal medicines for healthcare functions and has exhibited a positive impact on animal health. The present study aimed to investigate the effects of Alpiniae oxyphyllae fructus powder (AOP) on production performance, egg quality, egg yolk fatty acid composition, reproductive hormones, antioxidant capacity, immunity, anti-apoptosis ability, and intestinal health in hens. A total of 252 Hainan Wenchang laying hens (30-wk-old) were randomly divided into 3 groups with 6 replicates, a basic diet with 0 (CON), 1 g/kg AOP (AOP1), and 3 g/kg (AOP3) mixed AOP. The AOP supplementation was found to decrease the feed conversion ratio and embryo mortality but to increase the laying rate, average egg weight, and oviduct index linearly (p < 0.05). Furthermore, AOP treatment reduced the total saturated fatty acids and palmitic acid (C16:0) in the egg yolk while increasing eggshell strength, albumen height, and Haugh unit (p < 0.05). The serum levels of albumin and phosphorus were increased, whereas total cholesterol, triglycerides, and glucose levels decreased as a result of AOP treatment (p < 0.05). The inclusion of 3 g/kg AOP had higher 17 β-estradiol and follicle-stimulating hormone levels in serum, while it up-regulated follicle-stimulating hormone receptor and gonadotropin-releasing hormone expression in ovary (p < 0.05). Dietary AOP strengthened the expression of nuclear factor erythroid2-related factor 2 in ovary and increased the activity of superoxide dismutase and total antioxidant capacity, but had a lower malondialdehyde content in serum (p < 0.05). AOP at 3 g/kg up-regulated superoxide dismutase 1 and heme oxygenase 1 expression in jejunum and ovary (p < 0.05). Meanwhile, AOP supplementation down-regulated p53 expression in ovary and bcl-2-associated x expression in liver and jejunum, especially 3 g/kg of AOP had lower caspase-8 concentrations and down-regulated bcl-2-associated x and caspase-3 expression in ovary (p < 0.05). AOP treatment increased serum levels of immunoglobulin A and immunoglobulin M and upregulated interleukin-4 expression in the liver, while decreasing interleukin-1β expression in liver and ovary and nod-like receptor protein 3 expression in jejunum (p < 0.05). Dietary AOP increased the ratio of villus height to crypt depth but decreased crypt depth in jejunum, especially when 1 g/kg AOP increased expression levels of occludin, mucin-2, peptide-transporter 1, and sodium glucose cotransporter 1 in jejunum (p < 0.05). AOP treatment altered the composition of the cecal microbial community, as evidenced by increased abundance of Oscillospira and Phascolarctobacterium and reduced richness of Clostridiaceae_Clostridium. Dietary AOP supplementation enriched lipid, amino acid, and propanoate metabolism. Spearman's correlation analysis revealed that the genera Oscillospira, Blautia, and Megasphaera were related to laying performance and intestinal integrity. In brief, supplementation of AOP, especially at 3 g/kg, could improve production performance and egg quality of hens via modulating reproductive hormones, antioxidant capacity, immunity, intestinal barrier, and cecal microbiota. Overall, the present work recommends the dietary inclusion of AOP as a beneficial additive for improving the performance of hens.

Broiler Chicken Cecal Microbiome and Poultry Farming Productivity: A Meta-Analysis.

The cecal microbial community plays an important role in chicken growth and development via effective feed conversion and essential metabolite production. The aim of this study was to define the microbial community's variants in chickens' ceca and to explore the most significant association between the microbiome compositions and poultry farming productivity. The meta-analysis included original data from 8 control broiler chicken groups fed with a standard basic diet and 32 experimental groups supplemented with various feed additives. Standard Illumina 16S-RNA gene sequencing technology was used to characterize the chicken cecal microbiome. Zootechnical data sets integrated with the European Production Effectiveness Factor (EPEF) were collected. Analysis of the bacterial taxa abundance and co-occurrence in chicken cecal microbiomes revealed two alternative patterns: Bacteroidota-dominated with decreased alpha biodiversity; and Bacillota-enriched, which included the Actinomycetota, Cyanobacteriota and Thermodesulfobacteriota phyla members, with increased biodiversity indices. Bacillota-enriched microbiome groups showed elevated total feed intake (especially due to the starter feed intake) and final body weight, and high EPEF values, while Bacteroidota-dominated microbiomes were negatively associated with poultry farming productivity. The meta-analysis results lay the basis for the development of chicken growth-promoting feed supplementations, aimed at the stimulation of beneficial and inhibition of harmful bacterial patterns, where relevant metagenomic data can be a tool for their control and selection.

Intestinal microbiome profiles in broiler chickens raised without antibiotics exhibit altered microbiome dynamics relative to conventionally raised chickens.

The present study was undertaken to profile and compare the cecal microbial communities in conventionally (CONV) grown and raised without antibiotics (RWA) broiler chickens. Three hundred chickens were collected from five CONV and five RWA chicken farms on days 10, 24, and 35 of age. Microbial genomic DNA was extracted from cecal contents, and the V4-V5 hypervariable regions of the 16S rRNA gene were amplified and sequenced. Analysis of 16S rRNA sequence data indicated significant differences in the cecal microbial diversity and composition between CONV and RWA chickens on days 10, 24, and 35 days of age. On days 10 and 24, CONV chickens had higher richness and diversity of the cecal microbiome relative to RWA chickens. However, on day 35, this pattern reversed such that RWA chickens had higher richness and diversity of the cecal microbiome than the CONV groups. On days 10 and 24, the microbiomes of both CONV and RWA chickens were dominated by members of the phylum Firmicutes. On day 35, while Firmicutes remained dominant in the RWA chickens, the microbiome of CONV chickens exhibited am abundance of Bacteroidetes. The cecal microbiome of CONV chickens was enriched with the genus Faecalibacterium, Pseudoflavonifractor, unclassified Clostridium_IV, Bacteroides, Alistipes, and Butyricimonas, whereas the cecal microbiome of RWA chickens was enriched with genus Anaerofilum, Butyricicoccu, Clostridium_XlVb and unclassified Lachnospiraceae. Overall, the cecal microbiome richness, diversity, and composition were greatly influenced by the management program applied in these farms. These findings provide a foundation for further research on tailoring feed formulation or developing a consortium to modify the gut microbiome composition of RWA chickens.

Modulation of Immune Response and Cecal Microbiota by Dietary Fenugreek Seeds in Broilers.

Fenugreek seeds (FSs) are a natural source of bioactive compounds that may modulate the immune system and gut microbiota in broilers. This study examined the effects of dietary fenugreek seed powder on immune-related gene expression and cecal microbiota composition in broilers. A total of 144 broiler chickens were randomly allocated to three dietary groups, CON (0 g/kg FS, FS5 (5 g/kg FS) and FS10 (10 g/kg FS), each with 6 replicates of 8 birds. Ileum tissues and cecal contents were collected on day 42 for the mRNA expression of inflammation and antimicrobial defense-related genes and cecal microbiome diversity, respectively. The results indicated that fenugreek seeds downregulated mRNA-level inflammation and antimicrobial defense-related genes: IL6, IL8L2, CASP6, PTGS2, IRF7, AvBD9, AvBD10, and AvBD11. Moreover, fenugreek seeds altered the cecal microbial community by increasing the population of Firmicutes and decreasing the population of Actinobacteriota, Gemmatimonadota and Verrucomicrobiota at the phylum level and increasing Alistipes, Bacteriodes and Prevotellaceae at the genera level. These findings suggest that fenugreek seeds have a positive impact on the immunological profile and microbiome of broiler chickens, possibly through the interplay of the immune system and the gut microbiome.

Effects of Neolamarckia cadamba leaves extract on microbial community and antibiotic resistance genes in cecal contents and feces of broilers challenged with lipopolysaccharides.

The effects of Neolamarckia cadamba leaves extract (NCLE), with effective ingredients of flavonoids, on antibiotic resistance genes (ARGs) and relevant microorganisms in cecal contents and feces of broilers treated with or without lipopolysaccharide stimulation (LPS) were investigated. LPS stimulation increased (P < 0.05) the relative abundance of ARGs and mobile genetic elements (MGEs), such as tet(W/N/W), APH(3')-IIIa, ErmB, tet (44), ANT (6)-Ia, tet(O), tet (32), Vang_ACT_CHL, myrA, ANT (6)-Ib, IncQ1, tniB, and rep2 in cecal contents. However, the difference disappeared (P > 0.05) when NCLE was added at the same time. These differential ARGs and MGEs were mainly correlated (P < 0.01) with Clostridiales bacterium, Lachnospiraceae bacterium, and Candidatus Woodwardibium gallinarum. These species increased in LPS-stimulated broilers and decreased when NCLE was applied at the same time. In feces, LPS stimulation decreased (P < 0.05) the relative abundance of tet(Q), adeF, ErmF, Mef(En2), OXA-347, tet (40), npmA, tmrB, CfxA3, and ISCrsp1, while the LPS + NCLE treated group showed no significant effect (P > 0.05) on these ARGs. These differential ARGs and MGEs in feces were mainly correlated (P < 0.01) with Clostridiales bacterium, Pseudoflavonifractor sp. An184, Flavonifractor sp. An10, Ruminococcaceae bacterium, etc. These species increased in LPS-stimulated broilers and increased when NCLE was applied at the same time. In conclusion, LPS stimulation and NCLE influenced microbial communities and associated ARGs in both cecal contents and feces of broilers. NCLE alleviated the change of ARGs and MGEs in LPS-induced broilers by maintaining the microbial balance.IMPORTANCEAntibiotics showed a positive effect on gut health regulation and growth performance improvement in livestock breeding, but the antimicrobial resistance threat and environment pollution problem are increasingly severe with antibiotics abuse. As alternatives, plant extract containing bioactive substances are increasingly used to improve immunity and promote productivity. However, little is known about their effects on diversity and abundance of ARGs. Here, we investigated the effects of NCLE, with effective ingredients of flavonoids, on ARGs and relevant microorganisms in cecal contents and feces of broilers treated with or without lipopolysaccharide stimulation. We found that NCLE reduced the abundance of ARGs in cecal contents of lipopolysaccharide-induced broilers by maintaining the microbial balance. This study provides a comprehensive view of cecal and fecal microbial community, ARGs, and MGEs of broiler following LPS stimulation and NCLE treatment. It might be used to understand and control ARGs dissemination in livestock production.

The effects of β-mannanase supplementation on growth performance, digestive enzyme activity, cecal microbial communities, and short-chain fatty acid production in broiler chickens fed diets with different metabolizable energy levels.

This study assessed the effects of β-mannanase (BM) supplementation on growth performance, digestive enzyme activity, cecal microbial communities, and short-chain fatty acid (SCFA) production in broiler chickens fed diets with different metabolizable energy (ME) levels. A total of 1,296 male 1-d-old Cobb 500 broilers were randomly distributed in a 3 × 2 factorial arrangement (3 ME levels × 0 or 200g/ton BM), with 6 replicates per treatment combination. The 3 ME levels were 3,000 (ME1), 2,930 (ME2), and 2,860 (ME3) kcal/kg, respectively, during the 0 to 3 wk-old stages and 3,150 (ME1), 3,080 (ME2), and 3,010 (ME3) kcal/kg, respectively, during the 3 to 6 wk-old stages. Reducing ME levels increased broiler feed intake (P = 0.036) and decreased average daily gain (ADG, P = 0.002) during the entire period. While BM supplementation increased ADG (P = 0.002) and improved the feed conversion ratio (P = 0.001) during the 0 to 3 wk-old stages, with no effect during the 3 to 6 wk-old stages. Overall, reducing ME levels increased pancreatic lipase (P = 0.045) and amylase (P = 0.013) activity and duodenal amylase activity (P = 0.047). Notably, BM supplementation significantly increased pancreatic lipase activity (P = 0.015) and increased lipase (P = 0.029) and amylase (P = 0.025) activities in the jejunal chyme. Although diet or enzyme supplementation did not affect microbial diversity, significant differences in microbial communities were observed. At the genus level, decreasing ME levels significantly affected the average abundances of Tyzzerella (P = 0.028), Candidatus_Bacilloplasma (P = 0.001), Vibrio (P = 0.005), and Anaerotruncus (P = 0.026) among groups, whereas BM supplementation reduced the average abundances of Escherichia-Shigella (P = 0.048) and increased the average abundances of Barnesiella (P = 0.047), Ruminococcus (P = 0.020), Alistipes (P = 0.050), and Lachnospiraceae_unclassified (P = 0.009). SCFA concentrations strongly depended on bacterial community composition, and BM supplementation increased acetic acid (P = 0.004), propionic acid (P = 0.016), and total SCFA concentrations. In conclusion, BM supplementation improved the performance of younger broilers, and both enzyme supplementation and reduced ME levels positively affected digestive enzyme activity and intestinal microflora.

Panax notoginseng stems and leaves affect microbial community and function in cecum of duzang pigs.

Panax notoginseng is a Chinese medicine with a long history in which stems and leaves are the wastes of processing Panax notoginseng and have not been effectively utilized. The effects of diets containing Panax notoginseng stems and leaves on the cecal short-chain fatty acid (SCFA) concentration and microbiome of independent pigs were studied. Diets containing Panax notoginseng stems and leaves did not affect the concentration of SCFA in the cecal contents of Duzang pigs but affected the microbial composition and diversity. Firmicutes, Proteobacteria, and Bacteroidetes dominate in the cecal of Duzang pigs. Feeding Duzang pigs with a 10% Panax notoginseng stems and leaves diet increases the abundance of Lactobacillus, Christensenellaceae R-7 group, and Akkermansia in the cecal. We found 14 genera positively associated with acetate, and they were Lactobacillus, Ruminococcaceae UCG 005, Ruminiclostridium 6; Escherichia Shigella and Family XIII AD3011 group showed negative correlations. Solobacterium, Desulfovibrio, and Erysipelatoclostridium were positively associated with propionate. Campylobacter, Clostridium sensu stricto 11, and Angelakisella were positively associated with butyrate. In conclusion, Panax notoginseng stems and leaves could affect the cecal microbial community and functional composition of Duzang pigs. Panax notoginseng stems and leaves reduce the enrichment of lipopolysaccharide biosynthetic pathway of the cecal microbiome, which may have a positive effect on intestinal health. The higher abundance of GH25 family in Duzang pig's cecal microbiome of fed Panax notoginseng stems and leaves diet. This increase may be the reason for the microbial diversity decrease.

Effects of pomegranate (Punica granatum L.) peel on the growth performance and intestinal microbiota of broilers challenged with Escherichia coli

The effects of pomegranate peel on the growth performance, intestinal morphology, and the cecal microbial community were investigated in broilers challenged with avian pathogenic Escherichia coli (APEC) O78. A total of 240 one-day-old chicks (120 males and 120 females) were randomly and evenly allotted into 4 treatment groups (each with 6 biological replicates each of 10 chicks), i.e., negative control (NC), positive control (PC), and 2 experimental groups treated with 0.2% fermented pomegranate peel (FP) and 0.2% unfermented pomegranate peel (UFP), respectively, with PC, FP, and UFP groups challenged with APEC O78 (5 × 108 CFU) on day 14. Results showed that the challenge of APEC O78 decreased the body weight (BW) and average daily gain (ADG) of broilers from 1 to 28 d (P < 0.01). These broilers exhibited more pathological conditions in the heart and liver and higher mortality rates in 28 d compared to the NC group. Diet supplemented with pomegranate peel (either fermented or unfermented) significantly increased BW, ADG, and the villus height/crypt depth ratio (VCR) of small intestine in 28 d compared to the NC group (P < 0.05). Results of the taxonomic structure of the gut microbiota showed that compared to the NC group, the APEC challenge significantly decreased the relative abundance of Bacteroidetes and increased the relative abundance of Firmicutes (P < 0.01). Compared to the PC group, the relative abundance of Ruminococcus_torques_group in FP group was increased, while the relative abundance of Alistipes was decreased. In summary, our study showed that the dietary supplementation of pomegranate peel could maintain the intestinal microbiota at a state favorable to the host, effectively reduce the abnormal changes in the taxonomic structure of the intestinal microbiota, and improve the growth performance in broilers treated with APEC.

Effect of Lactobacillus salivarius SNK-6 on egg quality, intestinal morphology, and cecal microbial community of laying hens

The objective of this study was to investigate the effect of Lactobacillus salivarius (L. salivarius) SNK-6 supple-mentation on the laying performance, egg quality, blood parameters, intestinal morphology, and cecal microbial community of laying hens. A total of 432 healthy 30-wk-age laying hens were randomly divided into 3 groups with 6 replicates under the same husbandry and dietary regimes: control (CON); 2.0×108 CFU/kg L. salivarius supplementation (T1); 2.0×109 CFU/kg L. salivarius supplementation (T2). The experiment lasted for 10 wk. The results indicated that the supplementation resulted in a significant reduction in the broken egg and unqualified egg ratios, and a significant increase in the eggshell strength, eggshell relative weight, albumen height, and Haugh units (P < 0.05). The L. salivarius-treated hens exhibited significantly reduced serum malondialdehyde levels (P < 0.05); significantly increased total protein, phosphorus, calcitonin, and immunoglobulin M (P < 0.05); significantly increased cecal secretory immunoglobulin A concentration (P < 0.05); significantly improved villus height (VH) in the duodenum and VH to crypt depth ratio in the jejunum (P < 0.05). The serum globulin and interleukin-1β, immunoglobulin G concentrations, and catalase activity significantly increased in T2 (P < 0.05). Furthermore, the serum interferon-α level in T1 was significantly higher than that of the CON (P < 0.05). The intestinal barrier-related mRNA gene ZO-1, CLDN1, and MUC2 expression in the jejunum was significantly upregulated in the T1 and T2 groups (P < 0.05). The Firmicutes/Bacteroidetes ratio was higher and the relative abundances of Flavonifractor and Clostridiales_noname were significantly higher in the T1 group (P < 0.05). In conclusion, dietary supplementation with L. salivarius SNK-6 may improve hen egg quality, serum antioxidant capacity, immune function, and intestinal health.

Fat from Hermetia illucens Alters the Cecal Gut Microbiome and Lowers Hepatic Triglyceride Concentration in Comparison to Palm Oil in Obese Zucker Rats

BackgroundPalm oil (PO) is the most widely utilized plant oil for food production. Owing to the great ecologic problems associated with PO production, sustainably produced fats, such as insect fat, might be a suitable alternative. ObjectivesThe hypothesis was tested that fat from Hermetia illucens larvae (HF) compared with PO and soybean oil (SO) has no adverse effects on hepatic lipid metabolism, plasma metabolome, and cecal microbiome in obese Zucker rats. MethodsThirty male obese Zucker rats were randomly assigned to 3 groups (SO, PO, HF; n = 10 rats/group) and fed 3 different semisynthetic diets containing either SO, PO, or HF as the main fat source for 4 wk. The effects were evaluated by measurement of liver and plasma lipid concentrations, liver transcriptomics, targeted plasma metabolomics, and cecal microbiomics. ResultsSupplementation of HF reduced hepatic triglyceride concentration and messenger ribonucleic acid concentrations of selected genes involved in fatty acid and triglyceride synthesis in comparison to PO (P < 0.05). Pairwise comparison of the Simpson index and Jaccard index showed a higher cecal microbial α- and β-diversity in rats fed the HF diet than in rats fed the PO diet (P = 0.015 and P = 0.027), but no difference between rats fed the diets with SO or PO. Taxonomic analysis of the cecal microbial community revealed a lower abundance of Clostridium_sensu_stricto_1 and a higher abundance of Blautia, Mucispirillum, Anaerotruncus, Harryflintia, and Peptococcus in rats supplemented with HF than in rats supplemented with PO (P < 0.05). ConclusionsHF, compared with PO, has liver lipid-lowering effects in obese Zucker rats, which may be caused by a shift in the gut microbial community. Thus, HF might serve as a sustainably produced fat alternative to PO for food production.

Investigating the cecal microbiota of broilers raised in extensive and intensive production systems.

Intensive broiler production practices are structured to prevent the introduction and spread of pathogens; however, they can potentially minimize the exposure of broilers to beneficial commensal bacteria. In this study, we used 16S rRNA amplicon sequencing to characterize the cecal microbiota of 35-day-old broilers from 22 independent commercial farms rearing broilers under intensive (IPS) or extensive production systems (EPS). We aimed to determine which bacteria are normal inhabitants of the broiler ceca and which bacteria might be missing from broilers in IPS. In addition, we generated a collection of 410 bacterial isolates, including 87 different species, to be used as a resource to further explore the effects of selected isolates on bird physiology and to elucidate the role of individual species within the cecal microbial community. Our results indicated significant differences in the microbiota of broilers between systems: the microbiota of broilers from EPS was dominated by Bacteroidetes {55.2% ± 8.9 [mean ± standard deviation (SD)]}, whereas Firmicutes dominated the microbiota of broilers from IPS (61.7% ± 14.4, mean ± SD). Bacterial taxa found to be core in the EPS microbiota, including Olsenella, Alistipes, Bacteroides, Barnesiella, Parabacteroides, Megamonas, and Parasutterella, were shown to be infrequent or absent from the IPS microbiota, and the EPS microbiota presented higher phylogenetic diversity and greater predicted functional potential than that of broilers in IPS. The bacteria shown to be depleted in broilers from IPS should be further investigated for their effects on bird physiology and potential application as next-generation probiotics. IMPORTANCE Production practices in intensive farming systems significantly reduce the introduction and spread of pathogens; however, they may potentially minimize the exposure of animals to beneficial commensal microorganisms. In this study, we identified core bacteria from the cecal microbiota of broilers raised in extensive production systems that are missing or reduced in birds from intensive systems, including Olsenella, Alistipes, Bacteroides, Barnesiella, Parabacteroides, Megamonas, and Parasutterella. Furthermore, the cecal microbiota of broilers from extensive systems showed higher diversity and greater functional potential than that of broilers from intensive systems. In addition, a collection of bacterial isolates containing 87 different species was generated from the current study, and this important resource can be used to further explore the role of selected commensal bacteria on the microbial community and bird physiology.

Dietary peptide-specific antibodies against interleukin-4 differentially alter systemic immune cell responses during Eimeria challenge with minimal impacts on the cecal microbiota

Eimeria spp. induce host interleukin (IL)-4 production, a potent immune regulator, during coccidiosis to evade immune responses. Dietary anti-IL-4 may preserve bird performance during challenge; however, specific mechanisms have not been investigated. Study objectives were to develop peptide-specific anti-IL-4 antibodies and evaluate immune cell profiles and the cecal microbiota during Eimeria challenge. Four candidate IL-4 peptides were selected based on antigenicity and location. Hens were injected with conjugated peptide or carrier-only control (3/injection), eggs were collected post-vaccination and yolks were pooled by peptide before freeze-drying. On d 0, 300 Ross 708 broilers were placed in floor pens (10/pen) and assigned to 5 diets consisting of basal diet+2% egg yolk powder containing antibodies against 1 of 4 target peptides or carrier-only control for 14-d starter and grower periods (28 d total). Baseline blood and cecal contents were collected on d 14 (6 birds/diet) before half the remainder were inoculated with 10X Coccivac-B52 (Merck Animal Health, Kenilworth, NJ). Body weight (BW) and feed intake (FI) were recorded weekly and blood and cecal samples were collected at 3, 7, and 14 d post-inoculation (pi; 3/treatment). Immune cell profiles in peripheral blood mononuclear cells (PBMC) were evaluated flow cytometrically and cecal microbial communities determined by 16S/18S rRNA gene amplicon sequencing. Data were log-transformed when necessary and analyzed with diet, Eimeria, and timepoint fixed effects plus associated interactions (SAS 9.4; P ≤ 0.05). Anti-IL-4 did not alter baseline performance but generally increased PBMC Bu-1+ B cells 38.0 to 55.4% (P < 0.0001). Eimeria challenge reduced FI and BWG 16.1 and 30.3%, respectively, regardless of diet (P < 0.0001) with only birds fed peptide 4 antibodies not recovering feed conversion by d 28. Minimal diet-associated cecal microbiota changes were observed, indicating that anti-IL-4 effects were likely host-specific. Eimeria-challenged birds fed peptide 3 antibodies displayed minimal immune cell fluctuations compared to unchallenged counterparts, suggesting these antibodies potentially modulated intestinal immune responses to minimize systemic requirements, making them good candidates for further research.